I have never been there, so let´s check the reviews from Qype.com
The nice thing here is: everything is very relaxed. Because there’s no service walking around, you can sit in peace and enjoy the chilled music. When DJs play, one Euro from your first drink goes to the DJ. The food menu is a downloadable periodic table but also hung up at the bar. The crowd is mixed, somewhat gay, also a little bit sceney from first impressions, but both unobtrusive. Those who like the red-white not only on their chips but also on interior decoration will come here often. You can also lie down…
Nice bar with delicious juices, good beer and friendly people. You can have some privacy by closing the curtains around your hospital beds ;) At weekends they sometimes have excellent DJs playing.
It seems that Sanatorium23 used to be a psychiatric hospital before becoming a bar/club as described here:
Berlin is supposed to be the the Mecca of techno and EDM music.
That´s a great challenge as the public is very picky compared to some other European countries (Ireland I talk about you).
Just a last thing for today, when I took the S-Bahn (city train), I could not stop thinking about this scene from Berlin Calling :